A name can mean many things in the plant world

When we talk about plants, many of us have fallen into the unfortunate habit of using common names instead of the scientific ones. Although it might be intimidating to say Saxifraga stolonifera when one is far more comfortable calling that plant a strawberry begonia, these common names can be bewildering.

Once one gets past the daunting prospect of using Latin and Greek in ordinary conversation, scientific nomenclature is more useful than everyday terms. For one thing, it’s the only way to be certain that everyone is talking about the same plant.

S. stolonifera is a lovely plant also known as strawberry geranium, creeping rockfoil and mother of thousands. It is not a begonia, a strawberry or a geranium. It is a cousin of other rockfoils, however, and does produce many offshoots.

There are, however, several other plants called mother of thousands. One of these is the familiar houseplant, Chlorophytum taxum, aka spider plant or airplane plant, which should not be confused with the bromeliad we know as air plant (Tillandsia spp.). Another prodigious mother is a kalanchoe (Kalanchoe daigremontianum), also known as devil’s backbone.

Consider all the plants that we call “ivy.” This term has been applied to virtually any plant that grows as a vine — English ivy (Hedera helix), pothos (Epripremnum aureum), grape ivy (Cissus rhombifolia), poison ivy (Toxicodendron radicans) and the list goes on. A few of them are related, but only a few. None of the four I just listed is even a member of the same general family.

On the off chance that this wasn’t confusing enough, grape ivy is remotely related to grapes, but does not produce a tasty fruit.

Another term that is used frequently but inaccurately is “thistle.” All it takes for a plant to be called a thistle is that it is prickly. Russian thistle, which many of us know as tumbleweed, is more closely related to spinach, for example.

There are, of course, true thistles such as Canada thistle (Cursium arvense) or artichoke (Cynara cardunculus), whose leaves are certainly spiky. Although the invasive weed Malta star thistle (Centaurea melitensis) is not a true thistle, it is spiky and a cousin. The thistles and Centaurea are members of the sunflower family (Asteraceae), as is that salad essential, lettuce (Lactuca sativa).

If people tell you they really enjoy the bird of paradise plant, what do you envision? In the desert, we can grow two plants with that common name. One is Caesalpinia pulcherrima, and the other is C. gilliesii, two leguminous shrubs or shrubby trees that produce striking flowers, even during the worst of the Mojave summer.

The tropical bird of paradise (Strelitzia reginae or S. nicolai) is genetically closer to orchids and ginger than to its desert loving namesakes. Not surprisingly, the tropical plant is subject to sunscald when it is exposed to the southern Nevada sun for extended periods. Its extremely large leaves are not designed to withstand the winds that are so common in this region.

There are many more instances — wax flower may be Hoya carnosa, H. bella or Stephanotis floribunda (aka floradora). The third is a distant cousin of the other two. Other wax flowers include Monesis uniflora, a member of the wintergreen family, and Chamelaucium, a genus from Australia, related to the myrtles.

Several plants are called butterfly plants but they may or may not be genetically close; the common geranium is not actually a geranium, and these are just a few.

With so many sources of confusion when using nonstandard names, it makes sense to learn the scientific nomenclature. This can be especially important when buying a plant or looking up references, both online and in a book.

Some of these plants are edible; many are not. If you’re unsure whether it is safe for people and animals to eat or touch a plant, check with knowledgeable authorities before putting it in the ground.

The University of California Agriculture and Natural Resources website has a comprehensive list of safe and toxic plants. If you are concerned about the possibility of a plant having a negative effect, here is a link to that site: http://bit.ly/1KsrKoo. This listing is by common name, so be certain what plant you are investigating.

On a somewhat different note: A few weeks ago, I inadvertently made barrel cactus a claret cup cactus. This is one more reason to proofread; I thought I had written “hedgehog and barrel cacti with their claret cup and yellow flowers,” but somehow I left out those two first words.

Anyone who has been looking for a claret cup barrel cactus will be disappointed. There are a few barrel cactuses with lovely pink to magenta flowers, but most of the time, they are yellow.

Angela O’Callaghan is the Social Horticulture Specialist for University of Nevada Cooperative Extension. Contact ocallaghana@unce.unr.edu or 702-257-5581.